1. Field of the Invention
The invention is in the field of inflatable recreation devices formed, at least in part, by an inflatable donut-shaped tubular member.
2. Related Art
Inflatable donut-shaped tubular members, such as those commonly referred to as inner tubes, have long been used as flotation devices for water play. Such inflatable donut-shaped tubular members have also been used to form the supporting base of trampolines, such as shown in U.S. Pat. Nos. 3,130,816, 4,576,375, and 6,659,914, wherein a rebound surface extends over the top of the opening of the donut-shaped tubular member forming the base to provide the trampoline, and U.S. Pat. No. 5,813,946 wherein the rebound surface is formed by an inflatable floor extending across the bottom of the opening of the donut-shaped tubular member forming the base. U.S. Pat. No. 7,722,506 shows a step exercise device with a base formed of two stacked inflatable donut-shaped tubular members and a rigid top plate extending over the top of the upper donut-shaped tubular member and the opening therein so that the rigid top plate forms the top surface of the step. The step is used for performing step exercises or forms a platform, which may be unsteady, upon which a user can stand to perform other exercises or play games. All of the above devices are formed as the particular devices indicated, i.e., as a trampoline or as a step exercise device. They are not usable for a plurality of activities or to form a plurality of different recreational devices.